The Brake Equation

Driving in traffic the other day I was trying to name all of the instant warning signs on seeing another driver that will cause me grief on my drive. I know it's not a true mathematical representation but I thought it might be fun to present my findings like the Drake Equation, the equation designed to calculate the number of extaterrestrial civilizations in the Milky Way galaxy.

I present to you, the "Brake Equation":

T = fp • fs • fht• fm • ff • fa • L / 1000

T = Percent chance of a bad commutefp = Fraction of cars that are a Prius ("3" for 3%, etc)fs = Fraction of cars that are a Subarufht = Fraction of cars that are a Honda CR-V or Toyota RAV4fm= Fraction of cars that are a minivanff = Fraction of cars that are driven by a femalefa = Fraction of cars that are driven by an Asian over 30 years of ageL = Lane number, from the right, that the above drivers occupy (i.e. 3 = freeway 'passing' lane, 1 = slow lane)